Endotheliitis in COVID-19-positive patients after extremity amputation for acute thrombotic events.

INTRODUCTION: Both arterial and venous thrombotic events of the extremities occur in COVID-19 infection, but the etiology of these events remains unclear. This study sought to evaluate pathology specimens of COVID-19 positive patients post-amputation, who were found to have Rutherford 3 acute limb ischemia requiring amputation. METHODS: A retrospective review was performed of all vascular surgery emergency room and inpatient consultations in patients who presented to the Mount Sinai Health System from March 26, 2020 to May 10, 2020. Pathology specimens were examined using hematoxylin and eosin (H&E) stain. The specimens were assessed for the following: inflammatory cells associated with endothelium/apoptotic bodies, mononuclear cells, small vessel congestion, and lymphocytic endotheliitis. Of the specimens evaluated, two patients with a known history of peripheral vascular disease were excluded. RESULTS: Inflammatory cells associated with endothelium/apoptotic bodies were seen in all four patients and in four out of five specimens. Mononuclear cells were found in two out of four patients. Small vessel congestion was seen in all patients. Lymphocytic endotheliitis was seen in one out of four patients. CONCLUSION: This study shows endotheliitis in amputation specimens of four patients with COVID-19 disease and Rutherford Class 3 acute limb ischemia. The findings in these patients is more likely an infectious angiitis due to COVID-19.